Neuroscience (also known as neurobiology) is a science that studies the structure, function, development, pharmacology and pathology of the nervous system. In recent years, C. Cotardo has introduced coding theory into...Neuroscience (also known as neurobiology) is a science that studies the structure, function, development, pharmacology and pathology of the nervous system. In recent years, C. Cotardo has introduced coding theory into neuroscience, proposing the concept of combinatorial neural codes. And it was further studied in depth using algebraic methods by C. Curto. In this paper, we construct a class of combinatorial neural codes with special properties based on classical combinatorial structures such as orthogonal Latin rectangle, disjoint Steiner systems, groupable designs and transversal designs. These neural codes have significant weight distribution properties and large minimum distances, and are thus valuable for potential applications in information representation and neuroscience. This study provides new ideas for the construction method and property analysis of combinatorial neural codes, and enriches the study of algebraic coding theory.展开更多
Combinatorial optimization problems and ground state problems of spin glasses are crucial in various fields of science and technology.However,they often belong to the computational class of NP-hard,presenting signific...Combinatorial optimization problems and ground state problems of spin glasses are crucial in various fields of science and technology.However,they often belong to the computational class of NP-hard,presenting significant computational challenges.Traditional algorithms inspired by statistical physics like simulated annealing have been widely adopted.Recently,advancements in Ising machines,such as quantum annealers and coherent Ising machines,offer new paradigms for solving these problems efficiently by embedding them into the analog evolution of nonlinear dynamical systems.However,existing dynamics-based algorithms often suffer from low convergence rates and local minima traps.In this work,we introduce the dual mean-field dynamics into Ising machines.The approach integrates the gradient force and the transverse force into the dynamics of Ising machines in solving combinatorial optimization problems,making it easier for the system to jump out of the local minimums and allowing the dynamics to explore wider in configuration space.We conduct extensive numerical experiments using the Sherrington–Kirkpatrick spin glass up to 10000 spins and the maximum cut problems with the standard G-set benchmarks.The numerical results demonstrate that our dual mean-field dynamics approach enhances the performance of base Ising machines,providing a more effective solution for large-scale combinatorial optimization problems.展开更多
Measuring the lifecycle of low-carbon energy technologies is critical to better understanding the innovation pattern.However,previous studies on lifecycle either focus on technical details or just provide a general ov...Measuring the lifecycle of low-carbon energy technologies is critical to better understanding the innovation pattern.However,previous studies on lifecycle either focus on technical details or just provide a general overview,due to the lack of connection with innovation theories.This article attempts to fill this gap by analyzing the lifecycle from a combinatorial innovation perspective,based on patent data of ten low-carbon energy technologies in China from 1999 to 2018.The problem of estimating lifecycle stages can be transformed into analyzing the rise and fall of knowledge combinations.By building the international patent classification(IPC)co-occurrence matrix,this paper demonstrates the lifecycle evolution of technologies and develops an efficient quantitative index to define lifecycle stages.The mathematical measurement can effectively reflect the evolutionary pattern of technologies.Additionally,this article relates the macro evolution of lifecycle to the micro dynamic mechanism of technology paradigms.The sign of technology maturity is that new inventions tend to follow the patterns established by prior ones.Following this logic,this paper identifies different trends of paradigms in each technology field and analyze their transition.Furthermore,catching-up literature shows that drastic transformation of technology paradigms may open“windows of opportunity”for laggard regions.From the results of this paper,it is clear to see that latecomers can catch up with pioneers especially when there is a radical change in paradigms.Therefore,it is important for policy makers to capture such opportunities during the technology lifecycle and coordinate regional innovation resources.展开更多
A necessary and suffcient condition is given for the equation Ax4+ 1 =By2 to have positive integer solution, and an effective method is derived for solving equation a2x4 + 1 = By2 in positive integers x, y for given h...A necessary and suffcient condition is given for the equation Ax4+ 1 =By2 to have positive integer solution, and an effective method is derived for solving equation a2x4 + 1 = By2 in positive integers x, y for given ho and B completely. Also, using a recently result of Ribet, Darmon and Merel, we proved that Erdos’ conjecture on combinatorial number is right.展开更多
Objective:To evaluate simultaneous detection and differentiates of Brucella abortus(B.abortus) and Brucella melitensis(B.melitensis) through the combinatorial POR method.Methods:This study was designed using three pri...Objective:To evaluate simultaneous detection and differentiates of Brucella abortus(B.abortus) and Brucella melitensis(B.melitensis) through the combinatorial POR method.Methods:This study was designed using three primers that could simultaneously identify and differentiate two major species of pathogenic Brucella in humans and animals.Identification and differentiation of each species using the size of the PCR product were determined.To determine the specifieity of the method,bacteria close to the genus Brucella were used.Finally,to confirm PCR products.In addition to the products sequence,RFLP was performed on PCR products using restriction enzymes.Results:The method of optimized combinatorial PCR in this study could simultaneously detect and differentiate B.abortus and B.melitensis with high specificity and sensitivity in clinical samples.Differentiation of species is based on the resulting bands: therefore,the band 494 bp for B.abortus and 733 bp for B.melitensis were obtained.RFLP and sequencing results confirmed PCR results.Conclusions:The results of this study shows that without routine diagnostic methods such as culture and serology tests,using the molecular method of combinatorial PCR,important species of Brucella can be simultaneously identified and differentiated in clinical samples.展开更多
The increasing complexity of modern functional materials leads to the demandof a cost efficient tool for the development of new products. One possible approach to this questionis the adaptation of combinatorial method...The increasing complexity of modern functional materials leads to the demandof a cost efficient tool for the development of new products. One possible approach to this questionis the adaptation of combinatorial methods to the specific requirements of materials industry.These methods, originally developed for the pharmaceutical industry, have recently been applied tothe screening of superconductive, magnetoresistant and photoluminescent materials. The principle ofthese combinatorial approaches is the deposition of large materials libraries in one processcombined with fast methods for the determination of the resulting properties. In this paper, thedeposition and characterization of laterally graded materials libraries (composition spread) ispresented. The films have been deposited by reactive magnetron sputtering, using two or threemetallic targets at a low angle to the substrate surface as well as a system of apertures. Toillustrate the advantages of combinatorial approaches for the development of advanced materials, themulticomponent metastable hardcoatings (Ti,Al)N and Ti-Al-Si-N are discussed with special emphasison the relations between structure and composition on the one hand and the oxidation resistance ofthese coatings on the other. The results illustrate that the composition spread approach is apowerful and cost efficient tool for the development and optimization of new multicomponentfunctional materials.展开更多
Computational time complexity analyzes of evolutionary algorithms （EAs） have been performed since the mid-nineties. The first results were related to very simple algorithms, such as the （1＋1）-EA, on toy problems....Computational time complexity analyzes of evolutionary algorithms （EAs） have been performed since the mid-nineties. The first results were related to very simple algorithms, such as the （1＋1）-EA, on toy problems. These efforts produced a deeper understanding of how EAs perform on different kinds of fitness landscapes and general mathematical tools that may be extended to the analysis of more complicated EAs on more realistic problems. In fact, in recent years, it has been possible to analyze the （1＋1）-EA on combinatorial optimization problems with practical applications and more realistic population-based EAs on structured toy problems. This paper presents a survey of the results obtained in the last decade along these two research lines. The most common mathematical techniques are introduced, the basic ideas behind them are discussed and their elective applications are highlighted. Solved problems that were still open are enumerated as are those still awaiting for a solution. New questions and problems arisen in the meantime are also considered.展开更多
This paper is basically a survey to show a number of combinatorial optimization problems arising from VLSI circuit design. Some of them including the existence problem, minimax problem, net representation, bend minimi...This paper is basically a survey to show a number of combinatorial optimization problems arising from VLSI circuit design. Some of them including the existence problem, minimax problem, net representation, bend minimization, area minimization, placement problem, routing problem, etc. are especially discussed with new results and theoretical ideas for treating them. Finally, a number of problems for further research are mentioned.展开更多
Chemodynamic therapy(CDT)is considered as a promising modality for selective cancer therapy,which is realized via Fenton reaction-mediated decomposition of endogenous H_(2)O_(2) to produce toxic hydroxyl radical(•OH)f...Chemodynamic therapy(CDT)is considered as a promising modality for selective cancer therapy,which is realized via Fenton reaction-mediated decomposition of endogenous H_(2)O_(2) to produce toxic hydroxyl radical(•OH)for tumor ablation.While extensive efforts have been made to develop CDT-based therapeutics,their in vivo efficacy is usually unsatisfactory due to poor catalytic activity limited by tumor microenvironment,such as anti-oxidative systems,insufficient H_(2)O_(2),and mild acidity.To mitigate these issues,we have witnessed a surge in the development of CDT-based combinatorial nanomedicines with complementary or synergistic mechanisms for enhanced tumor therapy.By virtue of their bio-imaging capabilities,Fenton metal nanomedicines(FMNs)are equipped with intrinsic properties of imaging-guided tumor therapies.In this critical review,we summarize recent progress of this field,focusing on FMNs for imaging-guided combinatorial tumor therapy.First,various Fenton metals with inherent catalytic performances and imaging properties,including Fe,Cu and Mn,were introduced to illustrate their possible applications for tumor theranostics.Then,CDT-based combinatorial systems were reviewed by incorporating many other treatment means,including chemotherapy,photodynamic therapy(PDT),sonodynamic therapy(SDT),photothermal therapy(PTT),starvation therapy and immunotherapy.Next,various imaging approaches based on Fenton metals were presented in detail.Finally,challenges are discussed,and future prospects are speculated in the field to pave way for future developments.展开更多
A couple of additional cooling nozzles were assembled under traditionalatomization nozzles in order to improve the process and produce the powder with fine microstructureand low oxygen. The influence of the process pa...A couple of additional cooling nozzles were assembled under traditionalatomization nozzles in order to improve the process and produce the powder with fine microstructureand low oxygen. The influence of the process parameters on the properties of the powder wasinvestigated. The results show that finer powders with lower oxygen content and more irregular shapecan be achieved by combinatorial atomizing process comparing with normal one under the sameatomizing pressure.展开更多
Conventionally, an experimentally determined phase diagram requires studies of phase formation at a range of temperatures for each composition, which takes years of effort from multiple research groups. Combinatorial ...Conventionally, an experimentally determined phase diagram requires studies of phase formation at a range of temperatures for each composition, which takes years of effort from multiple research groups. Combinatorial materials chip technology, featuring high-throughput synthesis and characterization, is able to determine the phase diagram of an entire composition spread of a binary or ternary system at a single temperature on one materials library, which, though significantly increasing efficiency, still requires many libraries processed at a series of temperatures in order to complete a phase diagram. In this paper, we propose a "one-chip method" to construct a complete phase diagram by individually synthesizing each pixel step by step with a progressive pulse of energy to heat at different temperatures while monitoring the phase evolution on the pixel in situ in real time. Repeating this process pixel by pixel throughout the whole chip allows the entire binary or ternary phase diagram to be mapped on one chip in a single experiment. The feasibility of this methodology is demonstrated in a study of a Ge-Sb-Te ternary alloy system, on which the amorphouscrystalline phase boundary is determined.展开更多
An improved genetic algorithm is proposed to solve the problem of bad real-time performance or inability to get a global optimal/better solution when applying single-item auction （SIA） method or combinatorial auctio...An improved genetic algorithm is proposed to solve the problem of bad real-time performance or inability to get a global optimal/better solution when applying single-item auction （SIA） method or combinatorial auction method to multi-robot task allocation. The genetic algorithm based combinatorial auction （GACA） method which combines the basic-genetic algorithm with a new concept of ringed chromosome is used to solve the winner determination problem （WDP） of combinatorial auction. The simulation experiments are conducted in OpenSim, a multi-robot simulator. The results show that GACA can get a satisfying solution in a reasonable shot time, and compared with SIA or parthenogenesis algorithm combinatorial auction （PGACA） method, it is the simplest and has higher search efficiency, also, GACA can get a global better/optimal solution and satisfy the high real-time requirement of multi-robot task allocation.展开更多
Fast synthesis and screening of materials are vital to the advance of materials science and are an essential component of the Materials Genome Initiative. Here we use copper-oxide superconductors as an example to demo...Fast synthesis and screening of materials are vital to the advance of materials science and are an essential component of the Materials Genome Initiative. Here we use copper-oxide superconductors as an example to demonstrate the power of integrating combinatorial molecular beam epitaxy synthesis with high-throughput electric transport measurements. Leveraging this method, we have generated a phase diagram with more than 800 compositions in order to unravel the doping dependence of interface superconductivity. In another application of the same method, we have studied the superconductorto-insulator quantum phase transition with unprecedented accuracy in tuning the chemical doping level.展开更多
We study the construction of minimum bandwidth regenerating code with combinatorial design. At first, a method of constructing minimum storage regenerating （MBR） codes is presented, which can tolerate only one-node ...We study the construction of minimum bandwidth regenerating code with combinatorial design. At first, a method of constructing minimum storage regenerating （MBR） codes is presented, which can tolerate only one-node failure. Then, we give examples to explain the code. Finally, we discuss the case of repairing multiple nodes, and analyze the performance with an example.展开更多
This paper presents a novel regular Quasi-Cyclic (QC)Low Density Parity Check (LDPC)codes with columnweight three and girth at least eight.These are designed on the basis of combinatorial design in which subsets appli...This paper presents a novel regular Quasi-Cyclic (QC)Low Density Parity Check (LDPC)codes with columnweight three and girth at least eight.These are designed on the basis of combinatorial design in which subsets applied for the construction of circulant matrices are determined by a particular subset.Considering the nonexistence of cycles four and six in the structure of the parity check matrix,a bound for their minimum weight is proposed.The simtdations conducted confirm that without applying a masking technique,the newly implemented codes have a performance similar to or better than other well-known codes.This is evident in the waterfall region, while their error floor at very low Bit Error Rate (BER)is expected.展开更多
Combinatorial chemistry has been a focus of research activity in modern drug discovery and biotechnology. It is a concept by which a vast library of molecular diversity is synthesized and screened for target propertie...Combinatorial chemistry has been a focus of research activity in modern drug discovery and biotechnology. It is a concept by which a vast library of molecular diversity is synthesized and screened for target properties. This report is to illustrate the application of enzyme technology using the concept of combinatorial chemistry as a novel approach for the bioconversion of plant fibers. Citrus pectin was subjected to combinatorial enzyme digestion to create libraries of pectic oligosaccharides with diverse structural variants. Repeated cycles of fractionation and screening resulted in the isolation and identification of an active oligoGalA species with antimicrobial activity.展开更多
Polyketides have been widely used clinically due to their significant biological activities, but the needed structural and functional diversity cannot be achieved by common chemical synthetic methods. The tool of comb...Polyketides have been widely used clinically due to their significant biological activities, but the needed structural and functional diversity cannot be achieved by common chemical synthetic methods. The tool of combinatorial biosynthesis provides the possibility to produce "unnatural" natural drugs, which has achieved initial success. This paper provides an overview for the strategies of combinatorial biosynthesis in producing the structural and functional diversity of polyketides, including the redesign of metabolic flow, polyketide synthase(PKS) engineering, and PKS post-translational modification. Although encouraging progress has been made in the last decade, challenges still exist regarding the rational combinatorial biosynthesis of polyketides. In this review, the perspectives of polyketide combinatorial biosynthesis are also discussed.展开更多
Combinatorial chemistry involves the chemical or biological synthesis of diverse variation of the structures of a target molecule and the library is then screened for variants of desirable target properties. The appro...Combinatorial chemistry involves the chemical or biological synthesis of diverse variation of the structures of a target molecule and the library is then screened for variants of desirable target properties. The approach has been a focus of research activity in drug discovery and biotechnology. This report is to demonstrate the application of enzyme technology using the concept of combinatorial chemistry as a novel approach for the bioconversion of plant fibers. Wheat insoluble fiber was subjected to combinatorial enzyme digestion to create structural variants of feruloyl oligosaccharides (FOS). Fractionation and screening resulted in the isolation of a fraction of bioactive FOS species showing antimicrobial activity. These results demonstrate the feasibility and usefulness of the combinatorial enzyme technique in the transformation of plant biomass to value-added products.展开更多
This paper presents new half rate Quasi Cyclic Low Density Parity Check (QC- LDPC) codes formed on the basis of combinatorial designs. In these codes, circulant matrices of the parity check matrix are formed on the ba...This paper presents new half rate Quasi Cyclic Low Density Parity Check (QC- LDPC) codes formed on the basis of combinatorial designs. In these codes, circulant matrices of the parity check matrix are formed on the basis of subsets in which the difference between any two elements of a subset is unique with all differences obtained from the same or different subsets. This structure of circulant matrices guarantees non-existence of cycle-4 in the Tanner graph of QC-LDPC codes. First, an irregular code with girth 6 constituted by two rows of circulant matrices is proposed. Then, more criteria will be considered on the structure of subsets with the mentioned feature aiming to represent a new scheme of regular QC-LPDC codes with girth at least 8. From simulations, it is confirmed that codes have similar to or better performance than other well-known half rate codes, while require lower complexity in their design.展开更多
Thermoelectric materials have drawn extensive interest due to the direct conversion between electricity and heat,however,it is usually a time-consuming process for applying traditional“sequential”meth-ods to grow ma...Thermoelectric materials have drawn extensive interest due to the direct conversion between electricity and heat,however,it is usually a time-consuming process for applying traditional“sequential”meth-ods to grow materials and investigate their properties,especially for thermoelectric films that typically require fine microstructure control.High-throughput experimental approaches can effectively accelerate materials development,but the methods for high-throughput screening of the microstructures require further study.In this work,a combinatorial high-throughput optimization solution of material properties is proposed for the parallel screening and optimizing of composition and microstructure,which involves two distinctive types of high-throughput fabrication approaches for thin films,along with a new portable multiple discrete masks based high-throughput preparation platform.Thus,Bi_(2)Te_(3-x)Se_(x)thin film library with 196 throughputs for locating the optimized composition is obtained in one growth cycle.In addition,another thin film library composed of 31 materials with traceable process parameters is built to further investigate the relationship between microstructure,process,and thermoelectric performance.Through high-throughput screening,the Bi_(2)Te_(2.9)Se_(0.1)film with(00l)orientation is prepared with a peak zT value of 1.303 at 353 K along with a high average zT value of 1.047 in the interval from 313 to 523 K.This method can be also extended to the discovery of other functional thin films with a rapid combinatorial screening of the composition and structure to accelerate material optimization.展开更多
文摘Neuroscience (also known as neurobiology) is a science that studies the structure, function, development, pharmacology and pathology of the nervous system. In recent years, C. Cotardo has introduced coding theory into neuroscience, proposing the concept of combinatorial neural codes. And it was further studied in depth using algebraic methods by C. Curto. In this paper, we construct a class of combinatorial neural codes with special properties based on classical combinatorial structures such as orthogonal Latin rectangle, disjoint Steiner systems, groupable designs and transversal designs. These neural codes have significant weight distribution properties and large minimum distances, and are thus valuable for potential applications in information representation and neuroscience. This study provides new ideas for the construction method and property analysis of combinatorial neural codes, and enriches the study of algebraic coding theory.
基金supported by Projects 12325501,12047503,12247104,and 12322501 of the National Natural Science Foundation of ChinaProject ZDRW-XX-2022-302 of the Chinese Academy of Sciencespartially supported by the Innovation Program for Quantum Science and Technology project 2021ZD0301900。
文摘Combinatorial optimization problems and ground state problems of spin glasses are crucial in various fields of science and technology.However,they often belong to the computational class of NP-hard,presenting significant computational challenges.Traditional algorithms inspired by statistical physics like simulated annealing have been widely adopted.Recently,advancements in Ising machines,such as quantum annealers and coherent Ising machines,offer new paradigms for solving these problems efficiently by embedding them into the analog evolution of nonlinear dynamical systems.However,existing dynamics-based algorithms often suffer from low convergence rates and local minima traps.In this work,we introduce the dual mean-field dynamics into Ising machines.The approach integrates the gradient force and the transverse force into the dynamics of Ising machines in solving combinatorial optimization problems,making it easier for the system to jump out of the local minimums and allowing the dynamics to explore wider in configuration space.We conduct extensive numerical experiments using the Sherrington–Kirkpatrick spin glass up to 10000 spins and the maximum cut problems with the standard G-set benchmarks.The numerical results demonstrate that our dual mean-field dynamics approach enhances the performance of base Ising machines,providing a more effective solution for large-scale combinatorial optimization problems.
基金supported by the Natural Science Foundation of China(Grants No.42122006,42471187).
文摘Measuring the lifecycle of low-carbon energy technologies is critical to better understanding the innovation pattern.However,previous studies on lifecycle either focus on technical details or just provide a general overview,due to the lack of connection with innovation theories.This article attempts to fill this gap by analyzing the lifecycle from a combinatorial innovation perspective,based on patent data of ten low-carbon energy technologies in China from 1999 to 2018.The problem of estimating lifecycle stages can be transformed into analyzing the rise and fall of knowledge combinations.By building the international patent classification(IPC)co-occurrence matrix,this paper demonstrates the lifecycle evolution of technologies and develops an efficient quantitative index to define lifecycle stages.The mathematical measurement can effectively reflect the evolutionary pattern of technologies.Additionally,this article relates the macro evolution of lifecycle to the micro dynamic mechanism of technology paradigms.The sign of technology maturity is that new inventions tend to follow the patterns established by prior ones.Following this logic,this paper identifies different trends of paradigms in each technology field and analyze their transition.Furthermore,catching-up literature shows that drastic transformation of technology paradigms may open“windows of opportunity”for laggard regions.From the results of this paper,it is clear to see that latecomers can catch up with pioneers especially when there is a radical change in paradigms.Therefore,it is important for policy makers to capture such opportunities during the technology lifecycle and coordinate regional innovation resources.
基金Supported by the Natural Science Foundation of Heilongjiang Province
文摘A necessary and suffcient condition is given for the equation Ax4+ 1 =By2 to have positive integer solution, and an effective method is derived for solving equation a2x4 + 1 = By2 in positive integers x, y for given ho and B completely. Also, using a recently result of Ribet, Darmon and Merel, we proved that Erdos’ conjecture on combinatorial number is right.
基金supported by Molecular Biology Research Center,Baqiyatallah University of Medical Sciences,with grant number BMSU/MBRC- 89-009
文摘Objective:To evaluate simultaneous detection and differentiates of Brucella abortus(B.abortus) and Brucella melitensis(B.melitensis) through the combinatorial POR method.Methods:This study was designed using three primers that could simultaneously identify and differentiate two major species of pathogenic Brucella in humans and animals.Identification and differentiation of each species using the size of the PCR product were determined.To determine the specifieity of the method,bacteria close to the genus Brucella were used.Finally,to confirm PCR products.In addition to the products sequence,RFLP was performed on PCR products using restriction enzymes.Results:The method of optimized combinatorial PCR in this study could simultaneously detect and differentiate B.abortus and B.melitensis with high specificity and sensitivity in clinical samples.Differentiation of species is based on the resulting bands: therefore,the band 494 bp for B.abortus and 733 bp for B.melitensis were obtained.RFLP and sequencing results confirmed PCR results.Conclusions:The results of this study shows that without routine diagnostic methods such as culture and serology tests,using the molecular method of combinatorial PCR,important species of Brucella can be simultaneously identified and differentiated in clinical samples.
基金The financial support is granted by the Deutsche Forschungsgemeinschaft, Collabo-rative Research Center 289. "Forming of metals in the semi solid state and their properties" is gratefully acknowledged.
文摘The increasing complexity of modern functional materials leads to the demandof a cost efficient tool for the development of new products. One possible approach to this questionis the adaptation of combinatorial methods to the specific requirements of materials industry.These methods, originally developed for the pharmaceutical industry, have recently been applied tothe screening of superconductive, magnetoresistant and photoluminescent materials. The principle ofthese combinatorial approaches is the deposition of large materials libraries in one processcombined with fast methods for the determination of the resulting properties. In this paper, thedeposition and characterization of laterally graded materials libraries (composition spread) ispresented. The films have been deposited by reactive magnetron sputtering, using two or threemetallic targets at a low angle to the substrate surface as well as a system of apertures. Toillustrate the advantages of combinatorial approaches for the development of advanced materials, themulticomponent metastable hardcoatings (Ti,Al)N and Ti-Al-Si-N are discussed with special emphasison the relations between structure and composition on the one hand and the oxidation resistance ofthese coatings on the other. The results illustrate that the composition spread approach is apowerful and cost efficient tool for the development and optimization of new multicomponentfunctional materials.
基金This work was supported by an EPSRC grant (No.EP/C520696/1).
文摘Computational time complexity analyzes of evolutionary algorithms （EAs） have been performed since the mid-nineties. The first results were related to very simple algorithms, such as the （1＋1）-EA, on toy problems. These efforts produced a deeper understanding of how EAs perform on different kinds of fitness landscapes and general mathematical tools that may be extended to the analysis of more complicated EAs on more realistic problems. In fact, in recent years, it has been possible to analyze the （1＋1）-EA on combinatorial optimization problems with practical applications and more realistic population-based EAs on structured toy problems. This paper presents a survey of the results obtained in the last decade along these two research lines. The most common mathematical techniques are introduced, the basic ideas behind them are discussed and their elective applications are highlighted. Solved problems that were still open are enumerated as are those still awaiting for a solution. New questions and problems arisen in the meantime are also considered.
文摘This paper is basically a survey to show a number of combinatorial optimization problems arising from VLSI circuit design. Some of them including the existence problem, minimax problem, net representation, bend minimization, area minimization, placement problem, routing problem, etc. are especially discussed with new results and theoretical ideas for treating them. Finally, a number of problems for further research are mentioned.
基金supported by Innovation-Driven Project of Central South University (No. 20170030010004)National Natural Science Foundation of China (Nos. 21804144, U1903125, 82073799)
文摘Chemodynamic therapy(CDT)is considered as a promising modality for selective cancer therapy,which is realized via Fenton reaction-mediated decomposition of endogenous H_(2)O_(2) to produce toxic hydroxyl radical(•OH)for tumor ablation.While extensive efforts have been made to develop CDT-based therapeutics,their in vivo efficacy is usually unsatisfactory due to poor catalytic activity limited by tumor microenvironment,such as anti-oxidative systems,insufficient H_(2)O_(2),and mild acidity.To mitigate these issues,we have witnessed a surge in the development of CDT-based combinatorial nanomedicines with complementary or synergistic mechanisms for enhanced tumor therapy.By virtue of their bio-imaging capabilities,Fenton metal nanomedicines(FMNs)are equipped with intrinsic properties of imaging-guided tumor therapies.In this critical review,we summarize recent progress of this field,focusing on FMNs for imaging-guided combinatorial tumor therapy.First,various Fenton metals with inherent catalytic performances and imaging properties,including Fe,Cu and Mn,were introduced to illustrate their possible applications for tumor theranostics.Then,CDT-based combinatorial systems were reviewed by incorporating many other treatment means,including chemotherapy,photodynamic therapy(PDT),sonodynamic therapy(SDT),photothermal therapy(PTT),starvation therapy and immunotherapy.Next,various imaging approaches based on Fenton metals were presented in detail.Finally,challenges are discussed,and future prospects are speculated in the field to pave way for future developments.
文摘A couple of additional cooling nozzles were assembled under traditionalatomization nozzles in order to improve the process and produce the powder with fine microstructureand low oxygen. The influence of the process parameters on the properties of the powder wasinvestigated. The results show that finer powders with lower oxygen content and more irregular shapecan be achieved by combinatorial atomizing process comparing with normal one under the sameatomizing pressure.
基金supported in part by National High Technology Research and Development Program (2015AA034204)the National Natural Science Foundation of China (51472044)
文摘Conventionally, an experimentally determined phase diagram requires studies of phase formation at a range of temperatures for each composition, which takes years of effort from multiple research groups. Combinatorial materials chip technology, featuring high-throughput synthesis and characterization, is able to determine the phase diagram of an entire composition spread of a binary or ternary system at a single temperature on one materials library, which, though significantly increasing efficiency, still requires many libraries processed at a series of temperatures in order to complete a phase diagram. In this paper, we propose a "one-chip method" to construct a complete phase diagram by individually synthesizing each pixel step by step with a progressive pulse of energy to heat at different temperatures while monitoring the phase evolution on the pixel in situ in real time. Repeating this process pixel by pixel throughout the whole chip allows the entire binary or ternary phase diagram to be mapped on one chip in a single experiment. The feasibility of this methodology is demonstrated in a study of a Ge-Sb-Te ternary alloy system, on which the amorphouscrystalline phase boundary is determined.
基金Sponsored by Excellent Young Scholars Research Fund of Beijing Institute of Technology(00Y03-13)
文摘An improved genetic algorithm is proposed to solve the problem of bad real-time performance or inability to get a global optimal/better solution when applying single-item auction （SIA） method or combinatorial auction method to multi-robot task allocation. The genetic algorithm based combinatorial auction （GACA） method which combines the basic-genetic algorithm with a new concept of ringed chromosome is used to solve the winner determination problem （WDP） of combinatorial auction. The simulation experiments are conducted in OpenSim, a multi-robot simulator. The results show that GACA can get a satisfying solution in a reasonable shot time, and compared with SIA or parthenogenesis algorithm combinatorial auction （PGACA） method, it is the simplest and has higher search efficiency, also, GACA can get a global better/optimal solution and satisfy the high real-time requirement of multi-robot task allocation.
文摘Fast synthesis and screening of materials are vital to the advance of materials science and are an essential component of the Materials Genome Initiative. Here we use copper-oxide superconductors as an example to demonstrate the power of integrating combinatorial molecular beam epitaxy synthesis with high-throughput electric transport measurements. Leveraging this method, we have generated a phase diagram with more than 800 compositions in order to unravel the doping dependence of interface superconductivity. In another application of the same method, we have studied the superconductorto-insulator quantum phase transition with unprecedented accuracy in tuning the chemical doping level.
基金Supported by the National Natural Science Foundation of China(61271174,61301178)
文摘We study the construction of minimum bandwidth regenerating code with combinatorial design. At first, a method of constructing minimum storage regenerating （MBR） codes is presented, which can tolerate only one-node failure. Then, we give examples to explain the code. Finally, we discuss the case of repairing multiple nodes, and analyze the performance with an example.
文摘This paper presents a novel regular Quasi-Cyclic (QC)Low Density Parity Check (LDPC)codes with columnweight three and girth at least eight.These are designed on the basis of combinatorial design in which subsets applied for the construction of circulant matrices are determined by a particular subset.Considering the nonexistence of cycles four and six in the structure of the parity check matrix,a bound for their minimum weight is proposed.The simtdations conducted confirm that without applying a masking technique,the newly implemented codes have a performance similar to or better than other well-known codes.This is evident in the waterfall region, while their error floor at very low Bit Error Rate (BER)is expected.
文摘Combinatorial chemistry has been a focus of research activity in modern drug discovery and biotechnology. It is a concept by which a vast library of molecular diversity is synthesized and screened for target properties. This report is to illustrate the application of enzyme technology using the concept of combinatorial chemistry as a novel approach for the bioconversion of plant fibers. Citrus pectin was subjected to combinatorial enzyme digestion to create libraries of pectic oligosaccharides with diverse structural variants. Repeated cycles of fractionation and screening resulted in the isolation and identification of an active oligoGalA species with antimicrobial activity.
基金supported by the Major Research Plan of Tianjin(No.16YFXTSF00460)
文摘Polyketides have been widely used clinically due to their significant biological activities, but the needed structural and functional diversity cannot be achieved by common chemical synthetic methods. The tool of combinatorial biosynthesis provides the possibility to produce "unnatural" natural drugs, which has achieved initial success. This paper provides an overview for the strategies of combinatorial biosynthesis in producing the structural and functional diversity of polyketides, including the redesign of metabolic flow, polyketide synthase(PKS) engineering, and PKS post-translational modification. Although encouraging progress has been made in the last decade, challenges still exist regarding the rational combinatorial biosynthesis of polyketides. In this review, the perspectives of polyketide combinatorial biosynthesis are also discussed.
文摘Combinatorial chemistry involves the chemical or biological synthesis of diverse variation of the structures of a target molecule and the library is then screened for variants of desirable target properties. The approach has been a focus of research activity in drug discovery and biotechnology. This report is to demonstrate the application of enzyme technology using the concept of combinatorial chemistry as a novel approach for the bioconversion of plant fibers. Wheat insoluble fiber was subjected to combinatorial enzyme digestion to create structural variants of feruloyl oligosaccharides (FOS). Fractionation and screening resulted in the isolation of a fraction of bioactive FOS species showing antimicrobial activity. These results demonstrate the feasibility and usefulness of the combinatorial enzyme technique in the transformation of plant biomass to value-added products.
文摘This paper presents new half rate Quasi Cyclic Low Density Parity Check (QC- LDPC) codes formed on the basis of combinatorial designs. In these codes, circulant matrices of the parity check matrix are formed on the basis of subsets in which the difference between any two elements of a subset is unique with all differences obtained from the same or different subsets. This structure of circulant matrices guarantees non-existence of cycle-4 in the Tanner graph of QC-LDPC codes. First, an irregular code with girth 6 constituted by two rows of circulant matrices is proposed. Then, more criteria will be considered on the structure of subsets with the mentioned feature aiming to represent a new scheme of regular QC-LPDC codes with girth at least 8. From simulations, it is confirmed that codes have similar to or better performance than other well-known half rate codes, while require lower complexity in their design.
基金the National Key R&D Program of China(Grant No.2018YFA0702100)the National Natural Science Foundation of China(Grant No.U21A2079)+2 种基金the Beijing Natural Sci-ence Foundation(Grant No.2182032)the Zhejiang Provincial Key R&D Program of China(Grant Nos.2021C01026 and 2021C05002)and the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(No.2020R01007).
文摘Thermoelectric materials have drawn extensive interest due to the direct conversion between electricity and heat,however,it is usually a time-consuming process for applying traditional“sequential”meth-ods to grow materials and investigate their properties,especially for thermoelectric films that typically require fine microstructure control.High-throughput experimental approaches can effectively accelerate materials development,but the methods for high-throughput screening of the microstructures require further study.In this work,a combinatorial high-throughput optimization solution of material properties is proposed for the parallel screening and optimizing of composition and microstructure,which involves two distinctive types of high-throughput fabrication approaches for thin films,along with a new portable multiple discrete masks based high-throughput preparation platform.Thus,Bi_(2)Te_(3-x)Se_(x)thin film library with 196 throughputs for locating the optimized composition is obtained in one growth cycle.In addition,another thin film library composed of 31 materials with traceable process parameters is built to further investigate the relationship between microstructure,process,and thermoelectric performance.Through high-throughput screening,the Bi_(2)Te_(2.9)Se_(0.1)film with(00l)orientation is prepared with a peak zT value of 1.303 at 353 K along with a high average zT value of 1.047 in the interval from 313 to 523 K.This method can be also extended to the discovery of other functional thin films with a rapid combinatorial screening of the composition and structure to accelerate material optimization.
